We had 1,050 square feet of tile installed and grouted now 4-5 weeks later 4 areas have started to get cracked grout.

I was given two-three bags of grout out of the storage area of the local supply store and he brought me several additional bags the next day. I think the grout from his storage area was old grout because I have two bags left over and one of the coded numbers on the bag start with 10 for 2010 and the other one starts with 05 so the manufacture date of the grout must have been 2005 and it has been sitting in his shed for 5 years unclimate controlled.

He is telling me there is no expiration date on grout and it does not get old.

can i please have some input could this be bad grout or is it something else? He says my house must be shifting My house was built in 99 so I think the shifting must be over.

Entirely possible that shifting could be the culprit. Equally possible that a faulty installation is to blame. Can you give us any particulars about type of floor, support and how the tile was installed?

Finally, YES....grout that is old can certainly cause the problem. Never touch any that is over a year old...and even THAT old can be problematic if not stored properly!

"No expiration date?" He doesn't know what he's talking about.

__________________
Laz...

Avanti Tile & Stone
"Do Not Meddle In The Affairs Of Cats As They Are Subtle And Will Piss On Your Computer..."

The subfloor is 3/4 inch plywood and the installer put down mud and then 1/2 in cement board and the mud then tile. The installer told me the cracks were not near the seams of the cement board in one area because he could remeber where the seam was in that are the other area he was unsure.

I am not looking for an out with the grout I am looking for an answer to the cracks and then figure out how to fix it. The supply store is not taking any blame at all and I highly doubt they will do anything for me even if it is bad grout. I do not want to pay to have the entire floor regrouted and then have it crack again.

The installer came back and spend about three hours replacing the cracks that formed over the last couple weeks. I just want to be done with the project at this point and not deal with the floor even if that means to pay to re-grout the floor if that is the problem.

I am at work when I get home I will log on and post the code and brand of the grout.

Thanks for your input and ideas they will all help me figure out how to fix this

When the installer put down the 1/2" cement board, do you recall him covering the CBU joints with mesh tape? He might have also done it at the time the tile was installed.

Can you tell us if the cracks you saw were running parallel with the joists? Also be good to know if there were any parallel cracks running three feet or five feet apart. Those can be indicative of CBU joints that were not taped. It's one of the most common causes of cracked grout.